Tracking down the Duvaucel's geckos

Recent work by the Project Island Song monitoring team has given us an insight into what the reintroduced Duvaucel's gecko population has been up to, and how they might be faring in their new home.

Just after the reintroduction of 50 Duvaucel’s gecko in February a network of monitoring stations were set up with help provided by NorthTec’s Applied Science, Conservation and Environment students. The monitoring stations include a tracking tunnel which is designed so that when the lizards enter the tunnel, they walk over an ink pad and leave footprints on a tracking card. As the Duvaucel’s gecko is the largest lizard species in New Zealand, the adult geckos’ hefty footprints are reasonably easy to recognise. As anticipated, Duvaucel’s gecko footprints found in the tunnels have shown the monitoring team that the geckos are spreading out from the release sites into new territory.

Though the monitoring team are confident the population would have increased since they were introduced, with at least 30 of the geckos released being females pregnant with twins, it is still too early to determine how much the founder population has grown.

Unlike reintroduced bird species, identification bands cannot be used on geckos because they shed their skin, and would also shed their band. To help us identify individual Duvaucel’s geckos when monitoring, an identification 'photo fit' profile was created for each of the released geckos. Like human fingerprints, each gecko has unique scale markings which enable us to tell them apart. Each of the geckos’ profiles include a range of photos and other useful identifiers including claw patterns and sex. Monitoring is ongoing, and remote video monitoring is soon to be put in place thanks to funding provided through Pub Charity and Four Trusts.